The present invention relates to a quick connector having a function to verify that a pipe is correctly connected to the quick connector in snap-engagement relation, for example, adapted in assembly in a fuel piping of an automobile.
In a fluid piping structure, for example, a gasoline fuel piping structure where a tube is joined to a pipe, a connector is used for joining the tube to the pipe. In such piping system, for example, the pipe includes an inserting end portion on one axial side thereof wherein an annular engagement projection is formed on and around an outer peripheral surface. Then, the inserting end portion of the pipe is inserted and fitted in the connector so that the annular engagement projection snap-engages in the connector to provide locking relation between the pipe and the connector. Thereby connection between the pipe and the connector is completed. A quick connector adapted in this manner comprises a tubular connector housing provided with a tube connecting portion on one axial side thereof and an annular or generally annular retainer. The connector housing has a retainer holding portion on an opposite axial side, wherein at least one engagement window is provided, for example, a pair of engagement windows are provided in diametrically opposed relation with one another. The retainer is configured so that the annular engagement projection of the pipe snap-engages therewith, and is fitted in the retainer holding portion to engage with the engagement window. That is, the pipe is inserted in the retainer so that the annular engagement projection of the inserting end portion snap-engages with the retainer. Thereby the pipe is fitted in and connected to the quick connector. However, if an operator does not take care sufficiently to complete connection between the pipe and the connector, the inserting end portion of the pipe might not be fully inserted into the retainer or the connector and the annular engagement projection of the pipe might not snap-engage with the retainer. Thus, the pipe might be in so-called half-fitting relation with respect to the connector. In case of a piping system subject to operation while the pipe is incompletely connected to the connector, as sealing property by a sealing member between the connector and the pipe is insufficient or becomes insufficient, an inner fluid usually leaks out.
Then, in order to easily verify complete connection of a pipe to a quick connector, a checker is adapted to provide the connector with a function of verifying complete connection. A checker for verifying complete connection usually has a checker body configured to have inner surface curving along or generally along an outer peripheral surface of a connector housing. The checker body is provided with a pull-out portion and at least one engagement portion. The engagement portion is integrally formed on the checker body, for example, on opposite ends or opposite end portions respectively of the checker body. The checker is fitted on the connector housing, for example, an outer peripheral surface between engagement windows wherein the engagement portion engages with, for example, snap-engages with the engagement window to restrain movement of the checker in a pull-out direction. The checker is configured to be allowable for being pulled out by the engagement portion or engagement portions deflecting and moving, for example, radially outwardly, being pressed by the annular engagement projection when the pipe is correctly fitted in the connector and the annular engagement projection of the inserting end portion snap-engages with the retainer. Accordingly, upon completion of connection work of the pipe and the quick connector, it can be verified that the pipe is completely connected in the quick connector by pulling the checker out of the connector housing with the pull-out portion in a direction perpendicular to an axial direction of the connector housing. If the checker cannot be removed out of the connector housing when the checker is pulled, mostly the pipe is not completely connected to the quick connector. In such case, connection work of the pipe and the quick connector should be again implemented so that the inserting end portion of the pipe is fully inserted in the quick connector.
Meanwhile, in thus configured quick connector, a locking portion of the engagement portion of the checker to be engaged in or with the engagement window is formed typically short or small sized, so that the checker can be surely pulled out when the pipe is engaged with retainer. Hence, if the checker is pulled obliquely, for example, obliquely toward an opposite axial side of the connector housing, as the checker is inclined, and an engagement portion of the checker is deformed, engagement between the locking portion and the engagement window is likely to be released. In that event, it may occur that the checker is pulled out in spite of incomplete connection between the pipe and the quick connector. In order to avoid such inconvenience, JP, A, 11-344182 discloses a structure for verifying complete connection wherein a checker body is provided with an inclining restraint portion extending in an axial direction of the connector housing. The checker is fitted on the connector housing so that the inclining restraint portion contacts an outer peripheral surface of the connector housing and embraces a large diameter retainer holding portion of the connector housing from axial opposite sides thereof.
If the structure for verifying complete connection disclosed in JP, A, 11-344182 is applied, thanks to restraint force of the inclining restraint portion there is little danger that the checker is inclined even if the checker is pulled obliquely. Then, the checker is effectively prevented from being pulled out of the connector housing under incomplete connection between the pipe and the quick connector. However, the structure for verifying complete connection is configured to be adapted to a quick connector which is provided with a large diameter retainer holding portion on an opposite axial side of the connector housing and with a sufficiently large step or stepped portion on one axial end of the retainer holding portion. So, it is impossible or difficult to adapt this structure for verifying complete connection to a quick connector wherein a tube connecting portion is formed integrally and directly on one axial end of the retainer holding portion and a tube is fitted over up to a position of an opposite axial end of the tube connecting portion to generally even out a step or stepped portion or to reduce a step or stepped portion in height. And, in case that the inclining restraint portion providing a structure not to embrace a retainer holding portion from both axial opposite sides and to fit thereon, restraint effectiveness of the inclining restraint portion is reduced by half.
Further, in order to deal with a problem that a checker is easily pulled out when inclined, known is a structure as cited as a prior art in the JP, A, 11-344182 and as disclosed in U.S. Pat. No. 5,152,555. In this structure, slots are formed on one axial end positions of circumferential ends of engagement windows of a connector housing, and a checker is fitted on a connector housing so that portions near engagement portions of a checker body, i.e., leg portions are slip-fitted in the slots. However, the leg portions are fitted and mounted on the connector housing so as to embrace an outer peripheral surface thereof, and thereby are unlikely to move largely in an axial direction under external force. Hence, sometimes this structure for restraining the leg portions from moving axially may not be expected to provide a satisfactory function to effectively prevent inconvenience that the checker is pulled out accidentally or mistakenly.
Accordingly, it is an object of the present invention to provide a quick connector with function of verifying complete connection which enables to effectively prevent inconvenience that a checker is inclined due to axial movement of a checker body, even without adapting a step or step portion facing an axial direction of a retainer holding portion of a connector housing.
In order to achieve a foregoing object, there is provided a novel quick connector to be connected with a pipe which has an inserting end portion formed with an annular engagement projection, for example, on one axial side thereof, and having a function to verify complete connection with the pipe. The quick connector has a tubular connector housing. The tubular connector housing is provided with a tube connecting portion to be connected with a tube (including a hose or the like) on one axial side thereof or one side in a direction of an axis of the quick connector or the connector housing, and a retainer holding portion having at least one engagement window, for example, a pair of engagement windows in opposed relation with one another on an opposite axial side thereof or an opposite side in a direction of an axis of the quick connector or the connector housing. The quick connector also has an annular or generally annular retainer. The retainer is configured so that the annular engagement projection of the pipe snap-engages with the retainer when the inserting end portion of the pipe is inserted in the connector housing, and fitted to the retainer holding portion to engage with the engagement window (including a portion surrounding the engagement window). The quick connector further has a checker. The checker has a checker body configured so as to be along or generally along an outer peripheral surface of the connector housing or so as to include an inner surface being along or generally along an outer peripheral surface of the connector housing, for example, an outer peripheral surface between the engagement windows. The checker body is provided with a pull-out portion and integrally at least one engagement portion, for example, engagement portions formed on opposite ends or opposite end portions thereof respectively. The checker is fitted or mounted on an outer peripheral surface of the connector housing, for example, an outer peripheral surface between the engagement windows, being locked in a pull-out direction by engagement or snap-engagement between the engagement portion and the engagement window (including a portion surrounding the engagement window). The engagement portion of the checker body is pushed by the annular engagement projection, thereby deformed or deflected and moved, for example, radially outwardly, to allow the checker to be pulled out when snap-engagement between the annular engagement projection and the retainer brings about complete connection between the pipe and the quick connector. The connector housing or an outer peripheral surface of the connector housing, for example, an outer peripheral surface between the engagement windows is provided integrally with a pair of axial movement preventive means projecting radially outwardly in axially spaced relation with one another to restrain axial movement of the checker body. The axial movement preventive means respectively has one circumferential end portion and the other circumferential end portion circumferentially spaced a proper distance from the one circumferential end portion. The checker body of the checker is fitted in an axial space defined between a pair of the axial movement preventive means so as to be restrained to move toward one axial side and an opposite axial side of the connector housing. A portion of the checker body, for example, a portion around the pull-out portion which is likely to move largely in an axial direction under external force is locked against movement or displacement in an axial direction by contact or abutment with the axial movement preventive means. The engagement portion is designated to have a locking engagement function to lock in the engagement window, and a release function to unlock locking engagement by being pushed by the annular engagement projection of the pipe. Further, the engagement portion may also have a holding function in order that the checker is not released out of the connector housing quite easily, when locking engagement is unlocked. The engagement portion may be configured as inwardly directed engagement portion to seat in the engagement window.
Typically, the retainer is fitted in the retainer holding portion so that the pipe engagement portion to be engaged with the annular engagement projection of a pipe, for example, one axial end portion is shown in the engagement window. Also, typically the checker is fitted onto the connector housing so that an axial position of an engagement portion corresponds to an axial position of a pipe engagement portion of the retainer, for example, to an axial position of the annular engagement projection of the pipe in engagement with the retainer. If a pipe engagement portion of the retainer is formed as an engagement slit extending circumferentially on one axial end portion thereof, the retainer is fitted in the retainer holding portion so as to show the engagement slit in the engagement window, and the checker is fitted onto the retainer holding portion so that an axial position of the engagement portion corresponds to an axial position of the engagement slit, more specifically, so that a radially inner end of the engagement portion seats inside the retainer holding portion, further specifically in the engagement slit through the engagement window. The axial movement preventive means respectively is configured to lock the checker body against movement or displacement in an axial direction, in abutment or contact relation with the checker body of the checker fitted on the connector housing, for example, as stated above.
The axial movement preventive means respectively has one circumferential end portion and the other circumferential end portion circumferentially spaced a proper distance from the one circumferential end portion. That is, the axial movement preventive means respectively, for example, comprises an elongate rib formed integrally with one circumferential end portion, middle portion and the other circumferential end portion so as to extend circumferentially an appropriate length, or two raised portions (projecting portions or protrusions) properly spaced circumferentially with one another (one raised portion corresponds to one circumferential end portion and the other raised portion corresponds to the other circumferential end portion). So, when the checker is pulled obliquely, or an external force is exerted obliquely onto the checker and the checker body is pressed against the axial movement preventive means, the checker body is hardly deflected or kinked. Consequently, it is effectively prevented that the checker is pulled out accidentally. And, the axial movement preventive means may be formed so as to be across a certain circumferential distance on the connector housing. In this case, the axial movement preventive means are configured so that an entire of circumferential or widthwise length or a part of the checker body is fitted in an axial space defined therebetween. For example, a part of the checker body to be fitted in the axial space may be a circumferential or widthwise center portion of the checker body, or a portion around the pull-out portion of the checker body. If the axial movement preventive means are configured to fit only for a part of the checker body, it is easier to fit or mount the checker on the connector housing, compared to the case that the axial movement preventive means are configured to fit for an entire circumferential or widthwise length of the checker body. If an axial space between a pair of the axial movement preventive means is designed generally identical to thickness of the checker body, more specifically, thickness of a portion of the checker body to be fitted in the axial space defined therebetween, the checker is hardly inclined, for example, even if the checker is pulled obliquely in an axial direction. If the axial movement preventive means are formed as elongate rib, stability of the checker is enhanced. If the axial movement preventive means are formed as two raised portions, mounting property of the checker is further enhanced.
When pull force or the like is exerted on the checker body in a circumferential direction, the checker also might be pulled out depending on the configuration or the like of the engagement portion of the checker. Therefore, the checker body may be formed integrally with a pair of circumferential movement preventive means to prevent the checker body from movement toward one and the other circumferential directions in abutment or contact relation with one circumferential end and the other circumferential end of the axial movement preventive means. The circumferential movement preventive means on widthwise opposite sides of the checker body may be respectively configured as an axial projection integrally with the checker body. The checker body referred here is in state of being fitted on the connector housing, and the axial projection is extending axially of the connector housing.
When the pipe is correctly connected with the quick connector, locking engagement between the engagement portion of the checker and the engagement windows is released, and the released relation therebetween is maintained. In some cases, even if the checker is in released state, the checker is held in position, not to come off the connector housing very easily. However, usually, even in this state, if an operator touches carelessly the checker, it is fear that the checker comes off the quick connector, falls, for example, within a piping structure of an automobile, and is not accessible easily. Therefore, the checker body may be configured so that the axial projections are engaged with one circumferential end and the other circumferential end of the axial movement preventive means in a pull-out direction not to allow the checker body to come out easily between the axial movement preventive means when the checker body is fitted in an axial space between the axial movement preventive means.
A structure for verifying complete connection according to the present invention is suitable especially for a connector having a tube connecting portion integrally provided on one axial end of a retainer holding portion and being configured so that a tube is fitted over up to a position of an opposite axial end of the tube connecting portion.
A quick connector with function of verifying complete connection of present invention can effectively prevent that a checker is pulled out accidentally even if a connector housing has no specific stepped portion or stepped configuration on an outer peripheral surface thereof, and therefore has a function of verifying complete connection with a pipe accurately.
Now, the preferred embodiments of the present invention will be described in detail with reference to the drawings.